1. Field of the Invention
The invention generally relates to orthopedic devices. More specifically, the invention pertains to surgical implants used with spinal rods for the purpose of spinal fixation and correction of spinal curvature.
2. Description of Related Art
Spinal rods are often used for spinal fixation, including for correction of scoliotic curves. Fixation often involves implantation of such rods by attaching them to the spine with anchors in the form of hooks and/or pedicle screws. Often, a pair of rods are placed on opposite sides of the spine.
Various systems have been developed for rigidly connecting two spinal rods together to prevent rod migration and to increase stiffness of the paired rod assembly. In many cases involving multi-level fusion of the spine, these features are highly beneficial while stabilizing the spine construct until solid bone fusion is accomplished. In the post-operative period before fusion occurs, a significant amount of motion can occur between the rods, wires and hooks, which can, for example, allow a scoliotic correlation to decrease or the pelvis to de-rotate toward its previous, deformed position. By providing a rigid transverse connection between two spinal rods, the loss of correction can be reduced and a stiffer construct can be created, which may enhance the promotion of solid fusion.
It is sometimes the case that the two side-by-side spinal rods that are to be interconnected by a rod to rod connector are not perfectly parallel to each other. This is a problem for many rod to rod connectors of the prior art which do not permit for any angle between the two spinal rods.